Azithromycin Dosage: Simple Guide for Adults & Kids

If you’ve been prescribed azithromycin, you probably want to know how much to take and for how long. It’s a popular antibiotic because it works well against many bacterial infections and can be taken once daily. Below you’ll find the most common dosing schedules, what to watch out for, and a few tips to make the treatment smoother.

Standard Adult Dosing

For most infections in healthy adults, doctors use a 5‑day regimen known as the “Z‑pak.” You start with 500 mg on the first day, then 250 mg once a day for the next four days. This split‑dose works for things like strep throat, sinus infections, and certain sexually transmitted infections.

If you’re treating a lung infection such as atypical pneumonia, the dose may be higher: 500 mg once daily for three days straight. Some clinicians also prescribe 1 g (1000 mg) as a single dose for chlamydia. Always follow the exact plan your doctor gave you – the numbers can change depending on the bug you’re battling.

Take the pill with or without food; azithromycin isn’t picky. However, a full glass of water helps the tablet pass down your throat without irritation. If you miss a dose, take it as soon as you remember unless it’s almost time for the next dose. In that case, skip the missed one and continue the regular schedule – don’t double up.

Pediatric & Special Situations

Kids get a weight‑based dose. The usual recommendation is 10 mg per kilogram of body weight on day 1, then 5 mg/kg once daily for the next four days. For example, a child who weighs 20 kg would take 200 mg on the first day and 100 mg each day thereafter. Pediatric formulations often come in a liquid that’s easier to measure.

People with liver or kidney problems may need a lower dose, and older adults sometimes get a reduced schedule to avoid side effects. Pregnant or breastfeeding women should discuss dosing with their doctor, as azithromycin is generally considered safe but still requires professional guidance.

Alcohol doesn’t directly interact with azithromycin, but drinking heavily can worsen stomach upset, which is already a common side effect. If you notice severe diarrhea, stomach pain, or a rash, contact your healthcare provider right away – those could be signs of a more serious reaction.

Finally, finish the entire prescription even if you start feeling better. Stopping early can let the bacteria survive and become resistant, which makes future infections harder to treat.

In short, the typical adult schedule is 500 mg on day 1, then 250 mg daily for four days, while children get 10 mg/kg then 5 mg/kg. Adjustments are made for specific infections, organ function, and pregnancy. Stick to the plan, stay hydrated, and call your doctor if anything feels off. With the right dosing, azithromycin can clear up the infection quickly and safely.